July 22, 2019
Researchers at Heriot-Watt University’s Institute of Building and Urban Design, on behalf of the Wood Window Alliance, have determined that timber frames have a much lower cost over their lifespan than uPVC alternatives. This is largely due to the fact that timber frames have a significantly longer lifespan, as determined by a previous study, meaning timber frames made to Wood Window Alliance standards do not have to be replaced or repaired as often. Therefore, although uPVC windows may appear cheaper initially, timber frames prove to be a better investment over time.
The study covered three types of timber window and compared them all with uPVC alternatives:
- Modified timber
- Aluminium-clad timber
The frames were tested in three condition types to determine environmental factors:
Most suburban households in the UK exist in mild conditions, while high-rise and coastal properties typically experience more severe weather conditions. The study determined that timber frames of all types out-perform uPVC frames in mild conditions. In severe conditions, aluminium-clad timber frames performed the best, but all timber options proved to be better value than the uPVC alternative.
The study was carried out on a typical 1230 x 1480mm white, double-glazed ‘A’ rated casement window with one opening light. Costs were based on contract prices.
In mild conditions, the overall average cost over 100 years of each frame type was as follows:
In moderate conditions, the overall average cost over 100 years of each frame type was as follows:
In severe conditions, the overall average cost over 100 years of each frame type was as follows:
To see the full report, visit the Wood Window Alliance (www.woodwindowalliance.com).